The invention relates to a magnetic head unit for a magnetic tape apparatus, plastic mount essentially encloses the magnetic head casing behind the head face and has tape guide elements which guide the magnetic tape moved along the head face in the correct azimuth position. The connecting pins projecting from the rear wall of the head casing are joined to a connecting board to which the connecting cables are connected.
This kind of magnetic head unit has been previously disclosed in the patent application EP-A-0120518 to which co-pending U.S. patent application Ser. No. 558,069 filed Dec. 5, 1983 corresponds. The plastic mount of this known magnetic head unit is adhered to the magnetic head prior to the fitting of the latter and encloses it in a ring shape. Tape guide elements are moulded onto the plastic mounting and on adhesion of the mounting are aligned opposite the head face. Such alignment has the object of ensuring that with the aid of these tape guide elements the magnetic tape is always fed in front of the head face in the correct azimuth position. The consequence of this is that in the subsequent fitting of the magnetic head unit onto a head support the adjustment of the tape guide elements in relation to the head mirror is rendered unnecessary. Assembly is thus significantly simplified and may consist, for example, of simply clipping the head unit onto the support. With a suitable economical construction only plastic parts are then envisaged, which make ground between the magnetic head casing and the apparatus more difficult. Since grounding the magnetic head casing is always essential, this is achieved for the known magnetic head unit by means of separate pressure springs, which constitute a special component and must be fitted separately. These springs must also be electrically bonded with a ground lead.
It is also known from EP-A-0120518 for a circuit board to be mounted on the connecting pins projecting from the rear wall of the magnetic head, providing the connection between the magnetic head and the connecting cables. This board does not, however, offer any possibility of grounding the magnetic head casing.